i want to convert my 69 mustang from a c4 to a toploader with the soon to be 351w then a 408w im looking at the t5 trans but i read the toploader is way stronger (correct me if im wrong please) im leaning towards the toploader because i found one that has all new gaskets,fron and rear bearings and a new rear seal and it came out of 1969 fairlane with 390 engine. what is the max i should offer this guy? is this the big shaft toploader? please help

 

The input shaft is shorter on a big block toploader than it is on a small block toploader which means the shaft will barely sit in the pilot bushing located in the crankshaft if you install it behind a small block. Not good.







Also the tailshaft length and shifter mounting points will be different.


Lots of info here.


TOPLOADER HISTORY

 

It depends on several things. What all are you getting with the transmission? If its "rebuilt" does he have receipts? Is it a close ratio or wide ratio? Things like these can make the price vary.

 

There is a special deep pilot bushing available to use the 390 trans on a smallblock without modification.

 

cool do you know were i can find this special deep pilot bushing? i dont know if they have any receipts and its just the trans in the sale. its a wide ratio trans. it looks clean inside and out.. so what should i offer guys?

 

That shifter location can be a problem.. (Just say no to the recept saw)

 

any other bad things guys?

 

Yes, the toploader is indeed stronger than a T5.

The toploader you describe does not sound like it is rebuilt. Putting gaskets and seals in it is akin to a coat of paint. That said, rebuilding one is not normally a big deal. Constant mesh transmissions typically only need fresh brass and replacement of bearings that don't pass inspection.

 

Yeah. The 390 toploader is no stronger than the 289 toploader.

 

Yes, a top loader is a top loader EXCEPT for gearsets. Any toploader is pretty darn stout. It could also be said that a 289 toploader is as strong as an FE toploader.

The FE version will have a taller gearset than the one for a 289. This actually should work well with the motors you list. Both of these engines will be able to provide more get it rolling torque than a short stroke engine so the tighter ratio gearset should work good for you.